An off-by-one error is for example when you intend to perform a loop n times and write something like: for (int i = 1; i < n; ++i) { … } or: for (int i = 0; i <= n; ++i) { … } In the first case the loop will be executed (n – … Read more
$ perl -MO=Deparse -e ‘while () { }’ while (1) { (); } -e syntax OK It seems that while () {} and while (1) {} are equivalent. Also note that empty parens* are inserted in the empty block. Another example of pre-defined compiler behaviour: $ perl -MO=Deparse -e ‘while (<>) { }’ while (defined($_ … Read more
Ok, so first off, let me say this: Use while(true), as it gives the most semantic meaning. You need to parse for (;;) as it’s not something you see often. With that said, let’s analyze: Opcodes The code while(true) { break; } echo “hi!”; Compiles down to the opcodes: 0: JMPZ(true, 3) 1: BRK(1, 3) … Read more
Now someone told me that this is not very good programming because I use the return statement inside a loop and this would cause garbage collection to malfunction. That’s incorrect, and suggests you should treat other advice from that person with a degree of skepticism. The mantra of “only have one return statement” (or more … Read more
while file.readline().startswith(“#”): pass This uses the pass statement : The pass statement does nothing. It can be used when a statement is required syntactically but the program requires no action. http://www.network-theory.co.uk/docs/pytut/passStatements.html
That clearly depends on the particular implementation of the interpreter/compiler of the specific language. That said, theoretically, any sane implementation is likely to be able to implement one in terms of the other if it was faster so the difference should be negligible at most. Of course, I assumed while and for behave as they … Read more
A do..while can more directly be emulated in Go with a for loop using a bool loop variable seeded with true. for ok := true; ok; ok = EXPR { } is more or less directly equivalent to do { } while(EXPR) So in your case: var input int for ok := true; ok; ok … Read more
Yes* Yes, usually (and in your case) it does break out of the loop and returns from the method. An Exception One exception is that if there is a finally block inside the loop and surrounding the return statement then the code in the finally block will be executed before the method returns. The finally … Read more
PL/SQL: numeric or value error: character string buffer too small is due to the fact that you declare a string to be of a fixed length (say 20), and at some point in your code you assign it a value whose length exceeds what you declared. for example: myString VARCHAR2(20); myString :=’abcdefghijklmnopqrstuvwxyz’; –length 26 will … Read more
I usually write it like this: static String commaSeparated(String[] items) { StringBuilder sb = new StringBuilder(); String sep = “”; for (String item: items) { sb.append(sep); sb.append(item); sep = “,”; } return sb.toString(); }